Surface-mount thin-film fuse having compliant terminals

ABSTRACT

A surface-mountable thin-film fuse component is disclosed that may include a substrate having a top surface, a first end, and a second end that is spaced apart from the first end in a longitudinal direction. The thin-film component may include a fuse layer formed over the top surface of the substrate. The fuse layer may include a thin-film fuse track. An external terminal may be disposed along the first end of the substrate and electrically connected with the thin-film fuse track. The external terminal may include a compliant layer comprising a conductive polymeric composition.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims filing benefit of U.S. Provisional PatentApplication Ser. No. 62/841,917 having a filing date of May 2, 2019,which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present subject matter relates generally to surface-mount, thin-filmcomponents, and particularly to a surface-mount thin-film fuse havingcompliant terminals.

BACKGROUND OF THE INVENTION

Surface mounting has become a preferred technique for circuit boardassembly. As a consequence, virtually all types of electronic componentshave been or are being redesigned for surface mount (i.e., leadless)embodiments or applications. The rapid incorporation of surface mountdevices (SMD) into all types of electronic circuits has created acorresponding need for SMD fuses.

Fuses serve an essential function on many circuit boards. By fusing acircuit, selected sub-circuits and/or even certain individualcomponents, it is possible to prevent damage to an entire system whichmay otherwise result from failure of a single, local component.

Surface mount fuses often experience intermittent current surges, whichcan generate significant heat. As a result the fuse can experiencethermal cycling and thermal stresses. Thermal stresses can undesirablycause rigid terminations to detach from the surface to which the surfacemount fuse is mounted.

SUMMARY

In accordance with one embodiment of the present disclosure, asurface-mountable thin-film fuse component may include a substratehaving a top surface, a first end, and a second end that is spaced apartfrom the first end in a longitudinal direction. The thin-film fusecomponent may include a fuse layer formed over the top surface of thesubstrate. The fuse layer may include a thin-film fuse track. Anexternal terminal may be disposed along the first end of the substrateand electrically connected with the thin-film fuse track. The externalterminal may include a compliant layer comprising a conductive polymericcomposition.

In accordance with one embodiment of the present disclosure, a methodfor forming a surface-mountable thin-film fuse component is disclosed.The method may include providing a substrate having a first end and asecond end that is spaced apart from the first end in a longitudinaldirection. The method may include depositing a fuse layer formed overthe top surface of the substrate. The fuse layer may include a thin-filmfuse track. The method may include forming an external terminal alongthe first end of the substrate and connected with the fuse layer. Theexternal terminal may include a compliant layer including a conductivepolymeric composition.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling description of the presently disclosed subjectmatter, including the best mode thereof, directed to one of ordinaryskill in the art, is set forth in the specification, which makesreference to the appended figures, in which:

FIG. 1 illustrates a cutaway perspective view of an embodiment of asurface-mountable thin-film fuse component according to aspects of thepresent disclosure;

FIG. 2 illustrates a side elevation view of the embodiment of thesurface-mountable fuse component of FIG. 1, according to aspects of thepresent disclosure;

FIG. 3A illustrates a perspective view of another embodiment of asurface-mountable thin-film fuse component according to aspects of thepresent disclosure;

FIG. 3B illustrates a perspective view of a portion of the embodiment ofthe surface-mountable thin-film fuse component of FIG. 3A;

FIG. 4 is a flowchart of a method for forming a surface-mountablethin-film fuse component according to aspects of the present disclosure.

Repeat use of reference characters throughout the present specificationand appended drawings is intended to represent same or analogousfeatures, steps, or other elements of the present technology.

DETAILED DESCRIPTION OF REPRESENTATIVE EMBODIMENTS

It is to be understood by one skilled in the art that the presentdisclosure is a description of exemplary embodiments only, and is notintended as limiting the broader aspects of the present subject matter,which broader aspects are embodied in the exemplary constructions.

Generally, the present disclosure is directed to a surface-mountable(SMD) fuse including at least one external terminal including acompliant layer. Thin-film fuses often experience thermal cycling causedby current surges. During such thermal cycling, the compliant layers canprevent fracturing or detachment of the terminations from a mountingsurface to which the external terminal is attached.

The thin-film fuse component may include a substrate having a first endand a second end that is spaced apart from the first end in alongitudinal direction. A fuse layer that includes a thin-film fusetrack may be formed over the top surface of the substrate. A firstexternal terminal may be disposed along the first end of the substrateand connected with the thin-film fuse track. A second external terminalmay be disposed along the second end of the substrate and connected withthe thin-film fuse track.

As used herein, “formed over,” may refer to a layer that is directly incontact with another layer. However, intermediate layers may also beformed therebetween. Additionally, when used in reference to a bottomsurface, “formed over” may be used relative to an exterior surface ofthe component. Thus, a layer that is “formed over” a bottom surface maybe closer to the exterior of the component than the layer over which itis formed.

One or more of the external terminals may include a compliant layerincluding a conductive polymeric composition. The conductive polymericcomposition may include one or more suitable polymeric materials. As oneexample, the compliant layer may include an epoxy, a polyimide,amidoamine, phenolic, and/or siloxane epoxy. The polymer may include athermoset or thermoplastic resin.

The conductive polymeric composition may include conductive particles,which may be dispersed within the polymer (e.g., as a polymer matrix)and may improve the electrical conductivity of the compliant layer. Theconductive particle may be or include a metal, such as silver, gold,copper, etc. For example, conductive particles may be or include silver,copper, gold, nickel, tin, titanium, or other conductive metals. Thus,in some embodiments the compliant layer may include a silver-filledpolymer, nickel-filled polymer, copper-filled polymer etc.

In some embodiments, the one or more of the conductive particles mayinclude a layer of conductive material formed over a base material. Forinstance, one or more of the conductive particles may have a layer ofprecious metal (e.g., silver, gold, etc.) over a base metal (e.g.,copper).

The compliant layer may have a Young's modulus that is less than about20 GPa as tested in accordance with ASTM D638-14 at about 23° C. and 20%relative humidity, in some embodiments less than about 10 GPa, in someembodiments less than about 5 GPa, and in some embodiments less thanabout 3 GPa.

The compliant layer may exhibit low electrical resistance. For example,the compliant layer may exhibit a volume resistivity that is less thanabout 0.01 ohm-cm tested in accordance with ASTM B193-16, in someembodiments less than about 0.001 ohm-cm, and in some embodiments about0.0001 ohm-cm or less.

The compliant layer of the external terminations may be formed bydipping the monolithic body into a conductive polymeric compositionsolution to form a thick-film layer of the conductive polymericcomposition.

The fuse layer, which may include the thin-film element, may be formedusing a variety of suitable techniques. Examples of techniques that maybe employed include chemical deposition (e.g., chemical vapordeposition), physical deposition (e.g., sputtering), or any othersuitable deposition technique for forming thin-film elements. Additionalexamples include any suitable patterning technique (e.g.,photolithography), etching, and any other suitable subtractive techniquefor forming thin-film elements.

The fuse layer, which may include a thin-film element, may be or includea variety of suitable materials. For example, a variety of metals may beused, including copper, which has high conductivity and ductility. Insome embodiments, the thin-film element may be or include nickel (Ni).

The thickness of the fuse layer may vary. For example, in someembodiments thickness of the fuse layer may range from about 0.05microns to about 40 microns, in some embodiments from about 0.1 micronsto about 30 microns, in some embodiments from about 0.5 microns to about10 micron.

In some embodiments, the fuse track may be generally straight. It shouldalso be appreciated that other configurations are possible, for example,where additional length is required or desirable. As examples, in someembodiments, the fuse track may be curved, may zig-zag, or may have asinusoidal shape.

The fuse track may be configured to “fail” or “blow” (e.g., stopelectrically connecting the terminals together) when a current flowsthrough the fuse track that is over a maximum current within a specifiedtime. The maximum current may be related to the rated current of thefuse component. For example, the threshold current may be 250% of therated current for the fuse to blow within 5 seconds.

In other embodiments, the fuse may have a maximum current that rangesfrom about 0.1 amperes to about 4 amperes, or more, and in someembodiments from about 0.25 amperes to about 2 amperes. In otherembodiments, however, the fuse may be configured as an ultra-low currentfuse. In such embodiments, the maximum current of the fuse may rangefrom about 5 milliamperes (mA) to about 100 mA, in some embodiments fromabout 10 mA to about 75 mA, and in some embodiments from about 20 mA toabout 50 mA.

The thin-film fuse component may include at least one terminal. In someembodiments, the component may include a pair of terminals. In otherembodiments, however, the component may include greater than twoterminals. For example, in some embodiments the number of terminals mayrange from 2 to 12, or more, in some embodiments from 2 to 10, and insome embodiments from 2 to 8. The terminals may be arrangedsymmetrically about a longitudinal centerline, a lateral centerline, orboth. For example, the component may include 2 terminals on each side, 3terminals on each side, 4 terminals on each side, or more.

The terminal(s) may include multiple layers. The layers may be formedusing a variety of techniques, such as dipping, screen printing,electroplating, chemical deposition (e.g., chemical vapor deposition),physical deposition (e.g., sputtering), or any other suitable technique.

In some embodiments, the terminals may include a first layer formed overthe first end of the substrate and in electrical contact with thethin-film fuse track. The first layer of conductive material may be orinclude copper (e.g., formed using dipping or printing of a conductivepaste). In other embodiments, the first layer of conductive material maybe or include a variety of other suitable materials, such as gold,silver, platinum, nickel, copper, steel, or combination thereof. Thecompliant layer may be formed over the first layer. However, it shouldbe understood that multiple layers may be formed between the compliantlayer and the substrate.

In some embodiments, the terminal may include one or more additionalconductive layers formed over the compliant layer, which may be formedover the first layer. For example, a second layer may be formed over thecompliant layer. Thus, the compliant layer may be formed between thefirst layer and second layer. In some embodiments, a third layer may beformed over the second layer. The second and/or third layers maycomprise a solderable conductive material. For example, the second layermay be or include nickel. The third layer may be or include tin. Itshould be understood that the second and/or third layers alternativelymay be or include tin, nickel, lead, or mixtures thereof.

A thickness of the first layer of the terminal may range from about 10microns to about 200 microns, in some embodiments from about 15 micronsto about 100 microns, in some embodiments from about 15 microns to about80 microns, and in some embodiments from about 20 microns to about 60microns.

A maximum thickness of the compliant layer of the terminal may rangefrom about 10 microns to about 200 microns, in some embodiments fromabout 15 microns to about 100 microns, in some embodiments from about 15microns to about 80 microns, and in some embodiments from about 20microns to about 60 microns.

A ratio of the maximum thickness of the compliant layer to the thicknessof the fuse layer may range from about 0.25 to about 100, in someembodiments from about 0.3 to about 50, in some embodiments from about0.5 to about 30, in some embodiments from about 1 to about 20, in someembodiments from about 2 to about 10, and in some embodiments from about3 to about 8. For example, fuses having relatively small contact areas(corresponding with thin fuse layers) may benefit from relativelythicker compliant layers to mitigate thermal stresses at the contactareas between the fuse layer and external terminals. Thus, the aboveratios described may provide a more robust and reliable connectionbetween the fuse layer and the external terminals, thereby making thefuse more robust and reliable.

A thickness of the second layer of the terminal may range from about 1micron to about 30 microns, in some embodiments from about 2 microns toabout 20 microns, in some embodiments from about 3 microns to about 15microns, in some embodiments from about 4 microns to about 10 microns,e.g., about 7 microns.

An overall thickness of the terminal (e.g., including both the firstlayer and any subsequent layers, if present) may preferably range fromabout 15 microns to about 60 microns, and in some embodiments from about20 microns to about 40 microns.

The fuse layer may include one or more contact pads connected with thethin-film fuse track. A first contact pad may be electrically connectedwith the thin-film element, the contact pad extending to one of thefirst end or the second end of the substrate and electrically connectedwith one of the external terminal at the first end.

In some embodiments, the component may include at least one adhesionlayer formed over and/or beneath the fuse layer. The adhesion layer maybe or include a variety of materials that are suitable for improvingadhesion between the fuse layer and adjacent layers. For example, theadhesion layer may include at least one of Ta, Cr, TaN, TiW, Ti, or TiN.For example, in some embodiments, the adhesion layer may be or includetantalum (Ta) (e.g., tantalum or an oxide or nitride thereof) and may beformed between the fuse layer and substrate to improve adhesion. Asanother example, in some embodiments, the adhesion layer may be formedover the fuse layer and beneath a passivation layer, which is describedin greater detail below. Without being bound by theory, the material ofthe adhesion layer may be selected to overcome phenomena such as latticemismatch and residual stresses.

The adhesion layer(s) may have a variety of suitable thicknesses. Forexample, in some embodiments, the thickness of an adhesion layer mayrange from about 100 angstroms to about 2000 angstroms, in someembodiments from about 200 angstroms to about 800 angstroms, in someembodiments from about 400 angstroms to about 600 angstroms.

In alternative embodiments, the thin-film fuse component may include oneor more passivation layers formed over at least a portion of the fuselayer. The passivation layer may be applied over the fuse layer. Thepassivation layer may cover and protect the thin-film fuse from thedeposition process (e.g., electroplating) that is used to form theterminals. The passivation layer may be formed from a variety ofsuitable materials, including polymer materials. For example, in someembodiments, the passivation layer may be or include polyimide. In someembodiments, the passivation layer(s) may include at least one ofsilicon oxynitride, Al₂O₃, SiO₂, Si₃N₄, benzocyclobutene, or glass.

In some embodiments, a protective layer may be applied over thepassivation layer (if present) or directly over the fuse layer. Theprotective layer may have a thickness ranging from about 3 microns toabout 25 microns, in some embodiments from about 5 microns to about 20microns, and in some embodiments from about 7 microns to about 15microns. In some embodiments, multiple protective layers may beemployed.

The substrate, passivation layer, and/or protective layer may be formedfrom a variety of inorganic materials such as glass, ceramic, or aglass-ceramic mixture. The substrate may generally have a low thermalconductivity, such as less than about 10 W/(m·K), in some embodimentsless than about 5 W/(m·K), in some embodiments less than about 3W/(m·K), in some embodiments less than about 2 W/(m·K), and in someembodiments less than about 1 W/(m·K), and in some embodiments, greaterthan about 0.1 W/(m·K). In other embodiments, however, the substrate mayhave a thermal conductivity greater than 10 W/(m·K) and/For example, thesubstrate may include, silicon oxynitride, silicon oxide, silicon,alumina, sapphire, and/or another suitable material.

In some embodiments, the passivation layer, and/or protective layer maybe formed by depositing a paste (e.g., a glass paste, glass-ceramicpaste, etc.) followed by a firing step. Any suitable process, however,may be used to form the passivation layer and/or protective layer.

FIG. 1 is a perspective view of one embodiment of a surface-mountablethin-film fuse component 100 according to aspects of the presentdisclosure. FIG. 2 is a side elevation view of the surface-mountablethin-film fuse component 100 of FIG. 1 illustrating external terminalsthat include compliant layers. Referring to FIGS. 1 and 2, thesurface-mountable thin-film fuse component 100 may include a substrate102. The substrate 102 may have a top surface 104, a first end 106, anda second end 108 (FIG. 1) that is spaced apart from the first end 106 ina longitudinal direction 110.

A fuse layer 112 may be formed over the top surface 104 of the substrate102. The fuse layer 112 may include a thin-film fuse track 114. The fuselayer 112 may have a thickness 113 in a Z-direction 115 that is lessthan about 40 microns. The fuse track 114 may be generally straight, forexample as shown in FIG. 1. It should also be appreciated that otherconfigurations are possible, for example, where additional length isrequired or desirable. As examples, in some embodiments, the fuse track114 may be curved, may zig-zag, or may have a sinusoidal shape.

The fuse track 114 may be configured to “fail” or “blow” (e.g., stopelectrically connecting the terminals together) when a current flowsthrough the fuse track 114 that is over a maximum current within aspecified time (e.g., 5 seconds). The maximum current may be related tothe rated current of the fuse component. For example, the thresholdcurrent may be 250% of the rated current for the fuse to blow within 5seconds.

The fuse layer 112 may include a first contact pad 116 extending to thefirst end 106 of the substrate 102 and a second contact pad 118 (FIG. 2)extending to second end 108 of the substrate 102. The contact pads 116,118 may be integrally formed with the fuse track 114 during formation ofthe fuse layer 112. The second contact pad 118 may be generally similarto the first contact pad 116. For example, the contact pads 116, 118 maybe symmetric with respect to a lateral centerline 120 (FIG. 2). However,it should be understood that the contact pads 116, 118 may have anysuitable shape, including rectangular square, triangular, circular, etc.

The surface-mountable thin-film fuse component 100 may include one ormore passivation layers formed over the thin-film fuse layer 112. Forexample, a first passivation layer 122 may be formed over the thin-filmfuse layer 112. A second passivation layer 124 may be formed over thefirst passivation layer 122.

The surface-mountable thin-film fuse component 100 may include a firstexternal terminal 140 disposed along the first end 106 of the substrate102 and connected with the first contact pad 116 of the fuse layer 112.The surface-mountable thin-film fuse component 100 may include a secondexternal terminal 142 disposed along the second end 108 of the substrate102 and connected with the second contact pad 118.

For example, the first external terminal 140 may include a first baselayer 146 formed over the first end 106 of the substrate 102 andelectrically connected with the first contact pad 116. The secondexternal terminal 142 may include a second base layer 148 formed overthe second end 108 of the substrate 102 and electrically connected withthe second contact pad 118. The base layers 146, 148 may be formed bydipping the ends 106, 108 of the substrate 102 to form thick-film layersof a conductive material, such as copper, silver, gold, etc. In otherembodiments, however, the base layers 146,148 may be formed using othersuitable techniques such as plating (e.g., electrolytic or electrolessplating or combination thereof).

The first external terminal 140 may include a first compliant layer 150formed over the first base layer 146. The second external terminal 142may include a second compliant layer 152 formed over the second baselayer 148. The compliant layers 150, 152 may include a conductivepolymeric composition. For example, the conductive polymeric compositionmay include a polymeric material (e.g., an epoxy) and conductiveparticles, for example as described above.

The compliant layers 150, 152 may have respective maximum thicknesses153, 155 in the longitudinal direction 110. A ratio of the maximumthicknesses 153, 155 of the compliant layers 150, 152 to the thickness113 of the fuse layer 112 may range from about 0.25 to about 4.

The external terminals 140, 142 may include one or more plated layersformed over the compliant layers 150, 152. For example, the firstexternal terminal 140 may include a first plated layer 154 formed overthe first compliant layer 150. The second external terminal 142 mayinclude a first plated layer 156 formed over the second compliant layer152. In some embodiments, respective second plated layers 158, 160 mayoptionally be formed over the first plated layers 154, 156.

The plated layers 154, 156, 158, 160 may be formed of a variety ofsuitable metals. In one embodiment, the first plated layers 154, 156 mayinclude nickel. The second plated layers 158, 160 may include tin.However, any suitable combination of conductive materials may be usedfor the first plated layers 154, 156, and/or second plated layers 158,160. In other embodiments, however, the terminals 140, 142 may have adifferent plating configuration (e.g., be free of one or more of thefirst plated layers 154, 156 and/or the second plated layers 158, 160).

In some embodiments, a protective layer may be exposed along an exteriorof the surface-mountable thin-film fuse component 100 (e.g., appliedover the passivation layer(s) 122, 124 and/or a bottom surface 157 ofthe substrate 102). The protective layers may have thicknesses rangingfrom about 5 microns to about 25 microns. As examples, the protectivelayer(s) may include glass, ceramic, or a glass-ceramic mixture.

As one example, the passivation layer(s) 122, 124 may be or includeglass or a glass-ceramic mixture. The protective layer(s) may be formedover the second passivation layer 124 and may be or include glass or aglass-ceramic mixture.

FIG. 3A illustrates a perspective view of another embodiment of asurface-mountable thin-film fuse component 200 according to aspects ofthe present disclosure. FIG. 3B illustrates a perspective view of aportion of the surface-mountable thin-film fuse component 200 of FIG.3A. The surface-mountable thin-film fuse component 200 may be builtinclude a number of layers in substantially the same manner aspreviously described with reference to FIG. 1, starting with a glass,ceramic, or glass-ceramic substrate layer 202. A fuse layer 204 mayinclude a fuse track with integral contact pads 206 at each end thereof,for example as described above with reference to FIG. 1. The fuse layer204 may be formed by sputtering conductive material onto the substrate202, and then by patterning the fuse track and contact pads 206. Thefuse layer 204 may include copper or nickel. One or more adhesion layersmay be formed under the fuse layer 204 and/or over the fuse layer 204 toimprove adhesion between the fuse layer and adjacent layers (e.g., thesubstrate 202 and/or a first passivation layer 208).

The surface-mountable thin-film fuse component 200 may include a firstexternal terminal 242 disposed along a first end 250 of the substrate202 and connected with the first contact pad 206 of the fuse layer 204.The surface-mountable thin-film fuse component 200 may include a secondexternal terminal 244 disposed along the second end 252 of the substrate202 and connected with a second contact pad 254.

More specifically, referring to FIG. 3B, the surface-mountable thin-filmfuse component 200 may include a first adhesion layer 216 covering aconductive layer 226 (e.g., nickel) of the contact pad 206. Thesurface-mountable thin-film fuse component 200 may include a secondadhesion layer 236 formed over the conductive layer 226 of the contactpad 206. In this example, the conductive layer 226 and adhesion layers216, 236 (if present), may have a total thickness ranging from about 0.1microns to about 10 microns thick. The adhesion layers 216, 236 andconductive layer 226 may be successively sputtered over the substrate202 (FIG. 3A). In alternative embodiments, magnetic metals such as Ni,Co, Fe or their alloys, or other metals such as copper havingappropriate resistance/melting points may be employed. As discussedabove, other materials and configurations may also be employed.

In some embodiments, an electrode material 246 may be provided over andbe in contact with the conductive layer 226 (e.g., including nickel orcopper). The electrode material 246 may extend to an edge of thesubstrate 202 (FIG. 3A) such that the electrode material 246 contactsthe first external terminal 242 (FIG. 3A). Thus, the electrode material246 may increase a contact area between the fuse layer 206 and the firstexternal terminal 242 to form a more robust connection therebetween. Asa result, the fuse may be more resilient against thermal cycling andthermal stresses.

In an exemplary configuration, the electrode material 446 may be copper(Cu) and may be electroplated over the first passivation layer 216.Other methods for depositing the electrode material 246 may also beemployed as would be recognized by those of ordinary skill in the art.It should also be appreciated that the electrode material 246 may befabricated from conductive materials other than copper. In addition, itshould be understood that in some embodiments, the surface-mountablethin-film fuse component 200 may lack this additional electrode material246.

Referring again to FIG. 3A, following placement of the electrodematerial 246, a first passivation layer 208 of silicon oxynitride (SiNO)may be formed over the fuse layer 204. A second passivation layer 210(or protective sealing layer) may be formed over the passivation layer208. Finally a glass cover 212, or alternatively, other insulatingmaterial, may be applied. The end terminations 242, 244 may includecompliant layers and may generally be configured as described above withreference to FIG. 2.

FIG. 4 is a flowchart of a method 400 for forming a surface-mountablethin-film fuse component according to aspects of the present disclosure.In general, the method 400 will be described herein with reference tothe surface-mountable thin-film fuse components 100, 200 described abovewith reference to FIGS. 1 through 3B. However, it should be appreciatedthat the disclosed method 400 may be implemented with any suitable thinfilm fuse. In addition, although FIG. 4 depicts steps performed in aparticular order for purposes of illustration and discussion, themethods discussed herein are not limited to any particular order orarrangement. One skilled in the art, using the disclosures providedherein, will appreciate that various steps of the methods disclosedherein can be omitted, rearranged, combined, and/or adapted in variousways without deviating from the scope of the present disclosure.

The method 400 may include, at (402), providing a substrate having afirst end and a second end that is spaced apart from the first end in alongitudinal direction, for example as described above with reference toFIGS. 1 through 3B.

The method 400 may include, at (404), depositing a fuse layer formedover the top surface of the substrate. The fuse layer may include athin-film fuse track, for example as described above with reference toFIGS. 1 through 3B.

The method 400 may include, at (406), forming an external terminal alongthe first end of the substrate and connected with the fuse layer, forexample as described above with reference to FIGS. 1 through 3B. Theexternal terminal may include a compliant layer, which may include aconductive polymeric composition.

While the present subject matter has been described in detail withrespect to specific embodiments thereof, it will be appreciated thatthose skilled in the art, upon attaining an understanding of theforegoing may readily produce alterations to, variations of, andequivalents to such embodiments. Accordingly, the scope of the presentdisclosure is by way of example rather than by way of limitation, andthe subject disclosure does not preclude inclusion of suchmodifications, variations and/or additions to the present subject matteras would be readily apparent to one of ordinary skill in the art.

What is claimed is:
 1. A surface-mountable thin-film fuse componentcomprising: a substrate having a top surface, a first end, and a secondend that is spaced apart from the first end in a longitudinal direction;a fuse layer formed over the top surface of the substrate, the fuselayer comprising a thin-film fuse track; and an external terminaldisposed along the first end of the substrate and connected with thefuse layer, the external terminal comprising a compliant layercomprising a conductive polymeric composition, wherein: the fuse layerhas a fuse layer thickness in a Z-direction that is perpendicular to thetop surface of the substrate; the compliant layer has a maximumcompliant layer thickness in the longitudinal direction; and a ratio ofthe fuse layer thickness to the maximum compliant layer thickness rangesfrom about 0.25 to about
 100. 2. The surface-mountable thin-film fusecomponent of claim 1, wherein the conductive polymeric compositioncomprises an epoxy.
 3. The surface-mountable thin-film fuse component ofclaim 1, wherein the conductive polymeric composition comprisesconductive particles.
 4. The surface-mountable thin-film fuse componentof claim 3, wherein the conductive particles comprise silver.
 5. Thesurface-mountable thin-film fuse component of claim 1, wherein thethin-film fuse track has a thickness in the Z-direction that is lessthan about 40 microns.
 6. The surface-mountable thin-film fuse componentof claim 1, wherein the fuse layer further comprises a contact padelectrically connected with the thin-film fuse track, the contact padextending to one of the first end or the second end of the substrate andelectrically connected with one of the external terminal at the firstend.
 7. The surface-mountable thin-film fuse component of claim 6,wherein the external terminal comprises a first layer formed over thefirst end of the substrate and in electrical contact with the contactpad, and wherein the compliant layer is formed over the first layer. 8.The surface-mountable thin-film fuse component of claim 7, wherein thefirst layer comprises copper.
 9. The surface-mountable thin-film fusecomponent of claim 1, wherein the external terminal comprises a platedlayer over the compliant layer.
 10. The surface-mountable thin-film fusecomponent of claim 9, wherein the plated layer comprises at least one oftin or nickel.
 11. The surface-mountable thin-film fuse component ofclaim 1, wherein the surface-mountable thin film fuse componentcomprises a protective layer formed over the fuse layer.
 12. Thesurface-mountable thin-film fuse component of claim 11, wherein theprotective layer comprises glass.
 13. The surface-mountable thin-filmfuse component of claim 1, wherein the substrate comprises glass. 14.The surface-mountable thin-film fuse component of claim 1, wherein thesurface-mountable thin-film fuse component is designed to blow ifexposed to a maximum current that ranges from about 0.1 A to about 4 A.15. A surface-mountable thin-film fuse component comprising: a substratehaving a top surface, a first end, and a second end that is spaced apartfrom the first end in a longitudinal direction; a fuse layer formed overthe top surface of the substrate, the fuse layer comprising a thin-filmfuse track and a contact pad electrically connected with the thin-filmfuse track; and an external terminal disposed along the first end of thesubstrate and connected with the fuse layer, the external terminalcomprising a compliant layer comprising a conductive polymericcomposition, wherein: the contact pad extends to one of the first end orthe second end of the substrate and is electrically connected with theexternal terminal at the first end, the external terminal comprises afirst layer formed over the first end of the substrate and in electricalcontact with the contact pad, and the compliant layer is formed over thefirst layer.